Molded trimming



Patented June 14, 1938 .UNITED STATES PATENT OFFICE Edward R. Chatterton, D'elanco, N. J., assigner lto E. W. Tjwitchell Incorporated, Philadelphia Pa.,y a corporation of Delaware y Application June 1, 1936, seriai'No. y82.9.73

' c claims. (c1. 11i-53.5)

This invention lrelates `to improvements in shapedtrimmings or moldings of the class used on upholstery and extensively in automotive work for both inside `and outside nishing. Conventionally, these trimmings or molding materials are used as a ller in leather or upholstery-covered welts or gimps. l

Heretofore shaped trimmings or moldings of this class have consisted of a ller or core ofV suitable material embraced by a braided, interlaced or concatenated cover. Trimmings of this construction whilehaving the necessary flexibility and being susceptible to curves or bends without undue distortion of the molded` cross sectional shape have been unduly expensive Vdue to theunavoidable production limitations, it being possible to manufacture these products only at adrelatively slow production rate. As a consequence ofthe high cost of this product, its use has been seriously restricted. y Y

The object of my invention is tomake available to the consumers an efficient and durable trimming or molding of the classdescribed that will have the necessary flexibility and susceptibility to curves and bends without bodily distortion and at a price sui'liciently low to permit its use generally wherever a product of this nature may be required. y Y f In the practice of my invention I have produced by methods hereinafter described a composite cylindrical strand consisting of a central portion composed preferably of crushed paper and an outer portion consisting of a plurality of paper cords, either twisted or crushed, said cords being formed in spiral convolutions about the said central portion, and said central portion being twisted and compressed as a result of the application of the said cords thereto in spiral formation whereby the two portions form in effect an inter- 0 lockedunit wherein `the said cords are in effect embedded in the said central portion, and the latter portion in part is carried outwardly between the convolutions of the surrounding cords. This product differs from the prior conventional products, which employ as previously set forth a core embraced by an interlaced, braided or concatenated cover, inan essential respect. vIn these prior products, the interlaced, braided or concatenated. covers function merely as a containing envelope for the core which remains unaffected by the process of applying said cover. In my product on the other hand, by reason of the character of the stranding operation wherein the outer cords are assembled with the inner or central portion, the latter portion is compressed, twisted and interlocked with said cords in a manner integrating the outer and inner portions to an extent affording in eiect an integral structure wherein rthe parts combine to produce a stable elongated body having a distinct tendency to maintain its normal cross sectional form under even extreme bending conditions. Y

The cylindrical strand described above constitutes anintermediate product in the formation of the trimming or molding forming the subject 10 of myinvention. As a further step in the production of the finished product, I may or may not subject the cylindrical strand to a treatment with a suitable rubber suspension or solution, such, for example, as latex or a rubber cement, and l, subsequently subject the strand, treatedor untreated as the case may be, to a molding operation `to produce the desired cross sectional shape.

v The process of manufacture will be morereadily understood by reference to the attached drawl ing, in which: j

Figuresvl and 2 are, respectively, longitudinal and cross sectional Views of a section of the intermediate cylindrical product;

Fig. 3 isa cross sectional view showing the iinished product Vproduced bymolding the cylindrical intermediate product, and

Fig. i is a transverse sectional View illustrating a modification within the scope of the invention.y

With reference to Figs. l and 2, the reference numeral l designates the central portion which may, as previously set forth, consist of crushed paper. In this portion, I prefer to employ tissue paper. The outer cords which surround the inner portion l in spiral formation are indicated by the reference numeral 2. These cords, formed of paper, are preferably slack twisted to render them relatively pliable, although for certainA types of trimmings a hard twisted and, therefore, less pliable paper cord may be employed; or if extreme pliability is required, the cords may be formed merely of crushed paper. The elements I and 2 are assembled into the cylindrical strand in a twisting and stranding machine of well known type, wherein the elements in passing through a small die are compressed together and simultaneously twisted. As a result of this action, the spirally wound cords are forcibly embedded in the crushed paper. center and portions of the latter are pressed up between the convolutions of the cords, as illustrated in Fig. 2, and the elements are thereby united into a substantially' integral interlocked strand, which has a distinct tendency to maintain its original cross sectional form and condition even when sharply CTI bent. This unified strand, if desired, may now be passed through a bath of a rubber cementing medium or latex, and is again drawnthrough a die to force the rubber into the body of the strand and to remove the surplus rubber from the external surface. After a period of time, during which the rubber medium is permitted to set or cure, the treated strand is passed between the conventional molding rolls to give the strand a shape such, for example, as shown in Fig. 3, this molding operation leaving unaffected the aforedescribed desirable characteristics of the strand.

It has been found that a trimming or molding strip formed as described has no tendency to separate or disintegrate and constitutes an extremely eiiicient and durable'trimming or molding strip. It further has a distinct advantage over the prior conventional trimmings and moldings, in thatby reason of its method of fabrication it may be produced at a relatively high rate of speed and at low cost. For this reason it fills a definite requirement in the trade for an eiicient low-cost trimming or molding Inaterial, and is available for use in upholstery or nishing work for which the prior conventional moldings were unavailable by reason of their relatively high cost.

In Fig. 4, I have illustrated .a modification within the scope of the invention. In this case the trimming or molding strip is in all essential respects the same as that described above, but in addition is provided, longitudinally, with one or more flexible wires 3, which have the effect of maintaining the strip in bent or curved forms, this being a desirable feature for certain types of work.

While for general purposes the use of the crushed paper center is desirable, I have found that an entirely practicable trimming or molding strip may be formed bythe process described above utiliZin-g, however, only the cords 2. In such cases, the cords are passed through vthe twisting and stranding machine in the conventional manner, are thereafter treated with the rubber-bonding medium, Y and subsequently molded to the desired cross sectional shape. In this form of trimming, it is desirable to employ the rubber-bonding material by reason of the absence in the strand of the interlocking effect obtained, as described above, with the crushed paper center.

I claim:

1. A shaped trimming or molding strip consisting of a central portion of cr'ushed paper and an outer portion consisting of several strands of formed paper embracing the said central portion in spiral convolutions, the outer strands being embedded in said central portion and said central portion at the periphery thereof extending outwardly between and interlocking with the strands of the spirally-formed outer portion and forming with the latter a unied structure capable ofv flexure to curves or bends without material distortion from its normal cross sectional form.

2. A trimming or molding material in accordance with claim 1 wherein the elements are bonded together by means of a exible adhesive.

3. A shaped trimming or molding strip consisting of a central portion of crushed paper and an outer portion consisting of several cords of crushed paper embracing the central portion in spiral convolutions, the outer cords being embedded in said central portion and said central portion at the periphery thereof extending outwardly between and interlocking with the cords of the spirally-formed outer portion and forming with the latter a unified structure capable of flexure to curves or bends without material distortion from its normal cross sectional form.

4. A shaped trimming or molding strip consisting of a central portion of crushed paper and an outer portion consisting of several cords of twisted Vpaper embracing the central portion in spiral convolutions, said cords being. embedded in the central portion and said central portion at the periphery thereof extending outwardly between and interlocking with the cords of the spirally-formed outer portion and forming with the latter a unified structure capable of ilexure to curves or bends without material distortion from its normal cross sectional form.

5. A shaped trimming or molding strip as described in claim 3 and wherein the central portion is slightly twisted and further interlocks the core and the outer strands.

6. A shaped trimming or molding stripas described in claim 4 and wherein the central portion is slightly twisted and further interlocks the core and the outer strands.

EDWARD R. CHA'I'IERTON. 

